You can cut down the back of the bow and put overlays on for your nocks. This way you can keep the same bow length.
I cut them angled from the back to the belly so the overlay can be lower and not be a big bump on the back of the stave.
The overlay in the picture is cut a slight angle but I have done them at a much steeper angle. You will have to file lower than the groove you have already cut.
Here is a finished nock that has been cut and an angle.